Not if you specifically want to prevent this. A bitcoin private key is 256-bit ECDSA, which provides 128 bits of security. If you can remember a 10 word randomly generated diceware phrase[1], you can securely store bitcoins in your brain.
[1] calculating the private key as a SHA256(phrase) for example
Somehow, I don't think the government will leave you that option ;) You'll stay in prison and have the means to use the bitcoins confiscated or outlawed. They can also confiscate all your other assets, like the house your family lives in.
There are many options available to a sovereign government which mean that relying on purely technical measures will not defeat them, because they have a monopoly on force, up to and including lethal force.
Implemented correctly, it's much much more difficult to steal or seize than cash while at the same time being much much easier to smuggle to places with no extradition where money trumps the rule of law.
Just declare this person an enemy of the state/terrorist and there you go - to you and your encryption.
If he does I'd be very surprised if he can ever spend it, even if he does somehow get to a copy. Torture is not the only or most effective avenue to thwart encryption or your plans to keep money from them, they could claim enough back-taxes to bankrupt you, repossess anything you buy etc, etc.
You also have scenarios that are not as drastic, where the adversary is not a government but, for example, a powerful (ex-)spouse trying to seize some of the assets in illegal ways during a divorce going wrong. Etc.
Your refusal to acknowledge this usefulness of Bitcoin makes your criticism look weak and one-sided.